1. Field of the Invention
The present invention pertains to the field of computer system. More particularly, this invention relates to the art of safeguarding computer system users and components from electrical hazards.
2. Background
Many computer systems continually use a very small voltage as long as the system is connected to a power source. The voltage is present even when the computer system appears to be off. This is commonly referred to as sleep mode. In sleep mode, the voltage is used primarily to run an internal clock or maintain a small internal battery.
When a computer system is in sleep mode, a user may not suspect that voltage is present within the system, and may open the chassis without unplugging the computer system. Generally, the small amount of voltage used by the clock and internal battery in sleep mode is not dangerous to the user. The small voltage is also generally insufficient to damage components if the components are removed or replaced by an unsuspecting user.
Since there is little danger to the user or the components in these systems in sleep mode, historically there has been no need to safeguard the user and the components. However, computer system administrators often have problems with unqualified users opening a computer chassis and disturbing the components inside. As a result, mechanisms have been used to inform computer system administrators of past unauthorized accesses. For instance, a computer system can use a switch to trigger a latch within the computer system when the chassis is opened. Only a small amount of power is needed for this, so the small internal battery is sufficient to set the latch. The next time the computer system is turned on, the latched value can be recorded in memory by system software making it is accessible by the system administrator.
Advances in computer systems, however, have led to computer systems that use a larger amount of voltage, even in sleep mode. As long as the computer system is plugged in, even in sleep mode, as much as 5 V can be present in the system. In this case, an unsuspecting user who opens the chassis may experience an uncomfortable and potentially dangerous electrical shock even when the computer appears to be off. Additionally, the voltage is likely to be enough to damage components if the components are removed or replaced while the system is plugged-in. Memory boards, for example, could be destroyed by inserting or removing them under power. Also, when inserting or removing a printed circuit board, the voltage could short to nearby pins damaging components and creating a shock hazard.
Therefore, it would be beneficial to provide a safeguard for the protection of users and system components against electrical hazards when a voltage is present in a computer system and the chassis is opened.